Optimal Intravenous Dosing Strategies for Sedatives and Analgesics in the Intensive Care Unit

Remimazolam: An Updated Review of a New Sedative and Anaesthetic

Remimazolam (CNS7056) is a novel benzodiazepine for intravenous sedation; it has an ultra-short duration of action and was recently approved for use in procedural sedation and general anaesthesia. It acts on γ-aminobutyric acid type A receptors and is rapidly converted into an inactive metabolite by tissue esterase enzymes. Remimazolam has been successfully used in endoscopic inspection or surgery and general anaesthesia induction and maintenance with fast and predictable onset and recovery times, high procedure success rates, and minor respiratory and hemodynamic fluctuations and without serious drug-related adverse reactions. If needed, the effects of remimazolam can be reversed by flumazenil, which allows prompt termination of sedation. Although remimazolam has great potential for sedation in patients admitted to intensive care units, future studies are needed to evaluate its efficacy and safety in patients requiring sedation for a long period, and numerous studies are warranted to explore the optimal dose in different application scenarios. The review aimed to provide an introduction to the process of remimazolam synthesis and its current clinical uses and future clinical developments.

Guidelines for enhanced recovery after cardiac surgery. Consensus document of Spanish Societies of Anesthesia (SEDAR), Cardiovascular Surgery (SECCE) and Perfusionists (AEP)

The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved.

Patient-Specific Sedation Management via Deep Reinforcement Learning

Introduction: Developing reliable medication dosing guidelines is challenging because individual dose-response relationships are mitigated by both static (e. g., demographic) and dynamic factors (e.g., kidney function). In recent years, several data-driven medication dosing models have been proposed for sedatives, but these approaches have been limited in their ability to assess interindividual differences and compute individualized doses. Objective: The primary objective of this study is to develop an individualized framework for sedative-hypnotics dosing. Method: Using publicly available data (1,757 patients) from the MIMIC IV intensive care unit database, we developed a sedation management agent using deep reinforcement learning. More specifically, we modeled the sedative dosing problem as a Markov Decision Process and developed an RL agent based on a deep deterministic policy gradient approach with a prioritized experience replay buffer to find the optimal policy. We assessed our method's ability to jointly learn an optimal personalized policy for propofol and fentanyl, which are among commonly prescribed sedative-hypnotics for intensive care unit sedation. We compared our model's medication performance against the recorded behavior of clinicians on unseen data. Results: Experimental results demonstrate that our proposed model would assist clinicians in making the right decision based on patients' evolving clinical phenotype. The RL agent was 8% better at managing sedation and 26% better at managing mean arterial compared to the clinicians' policy; a two-sample t-test validated that these performance improvements were statistically significant (p < 0.05). Conclusion: The results validate that our model had better performance in maintaining control variables within their target range, thereby jointly maintaining patients' health conditions and managing their sedation.

Incidence of Inadequate Pain Treatment among Ventilated, Critically Ill Surgical Patients in a Thai Population

BACKGROUND

Inadequate pain treatment during intensive care unit stays causes many unfavorable outcomes. Pain assessment in mechanically ventilated patients is challenging because most cannot self-report pain. The incidence of pain among Thai surgical intensive care unit (SICU) patients has never been reported.

AIMS

To determine the inadequate pain control incidence among ventilated, critically ill, surgical patients.

DESIGN

Prospective, observational study.

SETTING

SICU of a university-based hospital during November 2017-January 2019.

PARTICIPANTS

Patients aged > 18 years, admitted to the SICU for a foreseeable duration of mechanical ventilation > 24 hours were included.

METHODS

On post-admission Day 2, each was assessed for pain at rest (every 4 hours) and during bed-bathing using the Critical Care Pain Observation Tool (CPOT; Thai version) or the 0-10 numeric rating scale (NRS). CPOT scores > 2 or NRS scores > 3 signified inadequate pain control, while a RASS score ≤ -3 was defined as overtreatment.

RESULTS

118 were included. The inadequate-pain-management incidence was 34% (n = 40) at rest and 29% (n = 34) during bed-bathing. The severe-pain incidence (NRS > 6, or CPOT > 5) was 5.9% (n = 7). Our incidence of overtreatment was 1.7%. The demographic data and ICU complication-rates of patients with adequate and inadequate pain treatment were similar.

CONCLUSIONS

Pain assessment tools in critically ill patients should be developed and validated to the language of the tool users in order to determine the incidence of pain accurately. The inadequate-pain-treatment incidence in ventilated critically ill, Thai surgical patients was lower than previously reported from other countries.

Potential Relationship between Cerebral Fractional Tissue Oxygen Extraction (FTOE) and the Use of Sedative Agents during the Perioperative Period in Neonates and Infants

Fractional tissue oxygen extraction (FTOE) by means of cerebral near-infrared spectroscopy (NIRS) provides information about oxygen uptake in the brain. Experimental animal data suggest that sedative agents decrease cerebral oxygen demand. The aim of the present study was to investigate the association between the cerebral FTOE and the use of pre and intraoperative sedative agents in infants aged 1-90 days. Cerebral NIRS was continuously applied during open major non-cardiac surgery in 46 infants. The main outcomes were the mean intraoperative FTOE and the percentage (%) of time of intraoperative hyperoxia_FTOE relative to the total duration of anesthesia. Hyperoxia_FTOE was defined as FTOE ≤ 0.1. Cumulative doses of sedative agents (benzodiazepines and morphine), given up to 24 h preoperatively, correlated with the mean intraoperative FTOE (Spearman's rho = -0.298, p = 0.0440) and were predictive for the % of time of intraoperative hyperoxia_FTOE (β (95% CI) 47.12 (7.32; 86.92)) when adjusted for the patients' age, type of surgery, preoperative hemoglobin, intraoperative sevoflurane and fentanyl dose, mean intraoperative arterial blood pressure, and end-tidal CO₂ by multivariate 0.75 quantile regression. There was no association with 0.5 quantile regression. We observed the suggestive positive association of decreased fractional cerebral tissue oxygen extraction and the use of sedative agents in neonates and infants undergoing surgery.

Critical Review and Meta-Analysis of Postoperative Sedation after Adult Cardiac Surgery: Dexmedetomidine Versus Propofol

OBJECTIVE

To evaluate reports from the published literature of all randomized clinical trials (RCT) comparing postoperative sedation with dexmedetomidine versus propofol in adult patients, after open cardiac surgery.

DESIGN

A computerized search on Medline, EMBASE, Web of Science, and Agency for Healthcare Research and Quality databases was completed through June 2020. Meta-analysis of all published RCT comparing dexmedetomidine versus propofol utilization in the postoperative phase, using the standard Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist.

SETTING

Assemblage and critical discussion of 11 RCTs comparing postoperative sedation from standard published reports from 2003 to 2019.

PARTICIPANTS

The study comprised 1,184 patients and analyzed critical discussion of time-based parameters (time to extubation, intensive care unit length of stay, and hospital length of stay) and nontime-dependent factors (delirium, bradycardia, and hypotension).

MEASUREMENTS AND MAIN RESULTS

Time to extubation was significantly reduced in the dexmedetomidine group (standardized mean difference [SMD] = -0.70, 95% confidence interval [CI] -0.98 to -0.42, p < 0.001); however, no difference in mechanical ventilation time was observed (SMD = -0.72, 95% CI -1.60 to 0.15, N.S.). Dexmedetomidine significantly reduced the intensive care unit length of stay (SMD = 0.23, 95% CI -1.06 to -0.16, p = 0.008), but this did not translate into a reduced hospital length of stay (SMD = -1.13, 95% CI -2.43 to 0.16, N.S). For nontime-dependent factors, incidence of delirium was unaffected between groups (odds ratio [OR]: 0.68, 95% CI 0.43-1.06, N.S), and higher rates of bradycardia (OR: 3.39, 95% CI: 1.20-9.55, p = 0.020) and hypotension (OR: 1.68, 95% CI 1.09-2.58, p = 0.017) were reported with propofol.

CONCLUSIONS

Despite the ICU time advantages afforded by dexmedetomidine over propofol, the former did not seem to contribute to an overall reduction in hospital length of stay or improvement in postoperative outcomes of heart valve surgery and CABG patients.

Terminal Withdrawal of Mechanical Ventilation: A Hospice Perspective for the Intensivist

The intensive care unit (ICU) and hospice inpatient unit (IPU) environments differ in many ways. Although both endeavor to provide the best care possible for their patients, the day-to-day goals of these environments are almost antithetical. Similarly, the experiences and expertise of the staff differ. When performing a similar clinical task, it may be addressed in different ways because each group is engrained in their primary day-to-day focus. Terminal withdrawal of mechanical ventilation is a procedure that is performed in both ICUs and some hospice IPUs. Previous examinations of this subject have been based largely upon the correlative background, practices, and perceptions of the ICU prescriber. The purpose of this review is to examine how the manner in which this procedure is performed in the hospice environment may differ in ways that the intensivist can incorporate into their own plan of care, or better appreciate when making the decision to remove mechanical ventilation in the critical care unit or transfer the patient to a hospice environment for the procedure to be completed.

Postoperative delirium

Delirium can be defined as an ‘acute brain dysfunction.’ Compared to dementia, which is a disease that deteriorates the brain function chronically, delirium shows very similar symptoms but is mostly ameliorated when the causative factors are normalized. Due to the heterogeneity in etiologies and symptoms, people including health care workers often mistake delirium for dementia or other psychiatric disorders. Delirium has attracted global interest increasingly and a vast amount of research on its management has been conducted. Experts in the field have constantly suggested that systematic intervention should be implemented through a team-based multicomponent approach aimed to reduce the incidence and duration of delirium. Surgery involves many health care workers with different expertise who are not familiar with delirium. For a team-based approach on the management of delirium, it is vital that all medical personnel concerned have a common understanding of delirium and keep in constant communication. Postoperative delirium is a common complication and exerts an enormous burden on patients, their families, hospitals, and public resources. To alleviate this burden, this article aimed to review general features and the latest evidence-based knowledge of delirium with a focus on postoperative delirium.

The Effect of Anesthesia on the Immune System in Colorectal Cancer Patients

Colorectal cancer (CRC) is the key leading cause of high morbidity and mortality worldwide. Surgical excision is the most effective treatment for CRC. However, stress caused by surgery response can destroy the body's immunity and increase the likelihood of cancer dissemination and metastasis. Anesthesia is an effective way to control the stress response, and recent basic and clinical research has shown that anesthesia and related drugs can directly or indirectly affect the immune system of colorectal cancer patients during the perioperative period. Thus, these drugs may affect the prognosis of CRC surgery patients. This review is intended to summarize currently available data regarding the effects of anesthetics and related drugs on perioperative immune function and postoperative recurrence and metastasis in CRC patients. Determining the most suitable anesthesia for patients with CRC is of utmost importance.

Sedation After Cardiac Surgery: Is One Drug Better Than Another?

The classic high-dose narcotic-based cardiac anesthetic has been modified to facilitate a fast-track, rapid recovery in the intensive care unit (ICU). Postoperative sedation is consequently now an essential component in recovery of the patient undergoing cardiac surgery. It must facilitate the patient's unawareness of the environment as well as reduce the discomfort and anxiety caused by surgery, intubation, mechanical ventilation, suction, and physiotherapy. Benzodiazepines seem well suited for this role, but propofol, opioids, and dexmedetomidine are among other agents commonly used for sedation in the ICU. However, what is an ideal sedative for this application? When compared with benzodiazepine-based sedation regimens, nonbenzodiazepines have been associated with shorter duration of mechanical ventilation and ICU length of stay. Current sedation guidelines recommend avoiding benzodiazepine use in the ICU. However, there are no recommendations on which alternatives should be used. In postcardiac surgery patients, inotropes and vasoactive medications are often required because of the poor cardiac function. This makes sedation after cardiac surgery unique in comparison with the requirements for most other ICU patient populations. We reviewed the current literature to try to determine if 1 sedative regimen might be better than others; in particular, we compare outcomes of propofol and dexmedetomidine in postoperative sedation in the cardiac surgical ICU.

A Review of Agents for Palliative Sedation/Continuous Deep Sedation: Pharmacology and Practical Applications

Continuous deep sedation at the end of life is a specific form of palliative sedation requiring a care plan that essentially places and maintains the patient in an unresponsive state because their symptoms are refractory to any other interventions. Because this application is uncommon, many providers may lack practical experience in this specialized area and resources they can access are outdated, nonspecific, and/or not comprehensive. The purpose of this review is to provide an evidence- and experience-based reference that specifically addresses those medications and regimens and their practical applications for this very narrow, but vital, aspect of hospice care. Patient goals in a hospital and hospice environments are different, so the manner in which widely used sedatives are dosed and applied can differ greatly as well. Parameters applied in end-of-life care that are based on experience and a thorough understanding of the pharmacology of those medications will differ from those applied in an intensive care unit or other medical environments. By recognizing these different goals and applying well-founded regimens geared specifically for end-of-life sedation, we can address our patients' symptoms in a more timely and efficacious manner.

Engaging Critically Ill Patients in Symptom Management: Thinking Outside the Box!

Caring for critically ill patients receiving mechanical ventilation in the intensive care unit (ICU) is an immense challenge for clinicians. Interventions to maintain physiological stability and life itself can cause a number of adverse effects that have a marked impact on patients beyond the period of critical illness or injury. These ICU-acquired conditions include but are not limited to weakness, depression, and post-intensive care syndrome, all of which markedly affect patients' quality of life after they leave the unit. How best to manage the many symptoms experienced by patients undergoing mechanical ventilation without contributing to adverse ICU-acquired sequelae remains a daunting charge for clinicians and requires innovative "out of the box" approaches to address these complex issues. Systematic, cutting-edge research is needed to challenge the "usual" way of managing ICU patients in order to provide the best available evidence for practice integration that minimizes adverse, ICU-acquired sequelae and improves outcomes for the most vulnerable patients. This article highlights a program of research focused on interventions for managing symptoms in critically ill patients receiving mechanical ventilatory support, including the appropriate empowerment of symptom self-management by patients undergoing mechanical ventilation. Development and testing of innovative, nontraditional interventions specifically tailored for ICU patients receiving mechanical ventilatory support are presented. Music listening is highlighted as a nonpharmacological, adjunctive intervention to reduce anxiety associated with mechanical ventilation. Patient-controlled sedation is discussed as an alternative method to meet patients' highly individual needs for sedative therapy to promote comfort.

Effect of carbamazepine or phenytoin therapy on blood level of intravenously administered midazolam: a prospective cohort study

Dental treatment of intellectually disabled patients is frequently performed under general anesthesia or sedation. Many of these patients have epilepsy and are medicated with antiepileptic drugs (AEDs). Carbamazepine (CBZ) and phenytoin (PHT) are known to promote the metabolism of midazolam, and the blood levels of midazolam in patients medicated with CBZ or PHT may be different from those in healthy individuals. In this study, we clarified the influences of CBZ and PHT on the blood level of intravenously administered midazolam in patients medicated with CBZ or PHT. The subjects were divided into the following groups: not medicated with AEDs (control group), medicated with only CBZ or PHT (mono CBZ/PHT group), and medicated with CBZ or PHT or both and other AEDs (poly CBZ/PHT group). General anesthesia was achieved using midazolam, propofol, and remifentanil, and then the blood midazolam level was measured at 10, 30, and 60 min after intravenous midazolam administration. According to the results, the blood midazolam level was significantly lower in the mono and poly CBZ/PHT groups than in the control group. This finding suggests that intravenously administered midazolam may have a weaker effect in patients medicated with CBZ or PHT.

Mutual relationship between anxiety and pain in the intensive care unit and its effect on medications

PURPOSE

Little is known about the relationship between anxiety and pain in intensive care unit (ICU) patients despite its importance. The aims of the present study are to examine the correlation between pain and anxiety during ICU care and to investigate its effects on the dose of opioids and anxiolytics administered.

METHODS

The study subjects were awake critically ill patients admitted to an ICU over a 2-month period. Trained psychiatrists evaluated the nondelirious, noncomatose patients daily for anxiety and pain using the Numeric Rating Scale for Pain (NRS-Pain), Faces Anxiety Scale (FAS), and Hamilton Anxiety Rating Scale.

RESULTS

Daily alterations of anxiety and pain were significantly correlated with one another among 123 patients. Both the FAS and the Hamilton Anxiety Rating Scale were positively correlated with the NRS-Pain (P < .001 for both). The NRS-Pain score (P = .016) and the FAS score (P = .007) both significantly correlated with the dose of anxiolytics. The dose of opioids was unaffected by the severity of pain or anxiety.

CONCLUSIONS

Pain and anxiety among critically ill patients in the ICU were closely correlated. Pain and anxiety influenced the dose of anxiolytics administered. Therefore, a precise evaluation and comprehensive approach to the management of pain and anxiety are important for treating ICU patients.

Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit

OBJECTIVE

To revise the "Clinical Practice Guidelines for the Sustained Use of Sedatives and Analgesics in the Critically Ill Adult" published in Critical Care Medicine in 2002.

METHODS

The American College of Critical Care Medicine assembled a 20-person, multidisciplinary, multi-institutional task force with expertise in guideline development, pain, agitation and sedation, delirium management, and associated outcomes in adult critically ill patients. The task force, divided into four subcommittees, collaborated over 6 yr in person, via teleconferences, and via electronic communication. Subcommittees were responsible for developing relevant clinical questions, using the Grading of Recommendations Assessment, Development and Evaluation method (http://www.gradeworkinggroup.org) to review, evaluate, and summarize the literature, and to develop clinical statements (descriptive) and recommendations (actionable). With the help of a professional librarian and Refworks database software, they developed a Web-based electronic database of over 19,000 references extracted from eight clinical search engines, related to pain and analgesia, agitation and sedation, delirium, and related clinical outcomes in adult ICU patients. The group also used psychometric analyses to evaluate and compare pain, agitation/sedation, and delirium assessment tools. All task force members were allowed to review the literature supporting each statement and recommendation and provided feedback to the subcommittees. Group consensus was achieved for all statements and recommendations using the nominal group technique and the modified Delphi method, with anonymous voting by all task force members using E-Survey (http://www.esurvey.com). All voting was completed in December 2010. Relevant studies published after this date and prior to publication of these guidelines were referenced in the text. The quality of evidence for each statement and recommendation was ranked as high (A), moderate (B), or low/very low (C). The strength of recommendations was ranked as strong (1) or weak (2), and either in favor of (+) or against (-) an intervention. A strong recommendation (either for or against) indicated that the intervention's desirable effects either clearly outweighed its undesirable effects (risks, burdens, and costs) or it did not. For all strong recommendations, the phrase "We recommend …" is used throughout. A weak recommendation, either for or against an intervention, indicated that the trade-off between desirable and undesirable effects was less clear. For all weak recommendations, the phrase "We suggest …" is used throughout. In the absence of sufficient evidence, or when group consensus could not be achieved, no recommendation (0) was made. Consensus based on expert opinion was not used as a substitute for a lack of evidence. A consistent method for addressing potential conflict of interest was followed if task force members were coauthors of related research. The development of this guideline was independent of any industry funding.

CONCLUSION

These guidelines provide a roadmap for developing integrated, evidence-based, and patient-centered protocols for preventing and treating pain, agitation, and delirium in critically ill patients.

Protocolized and target-based sedation and analgesia in the ICU

Protocolized target-based sedation and analgesia is central to effective management of sedation. Important components include identifying goals and specific targets,using valid and reliable tools to measure pain, agitation, and sedation, and titrating a logically selected combination of sedatives and analgesics to defined end-points.A variety of approaches to structured management have been tested in controlled trials with major categories of (1) sedation algorithms and protocols and (2) daily interruption of sedation. Although not all studies that compare new interventions to “usual care” document dramatic improvements, many studies show that by reducing oversedation, using a structured approach, faster recovery from respiratory failure may ensue. The somewhat discrepant results illustrate, however, that various approaches,such as DIS, may not be optimal for all patients. Further research will be necessary to define these patients and examine alternative strategies. Finally, implementation of structured approaches to sedation management is a challenging, time-consuming process for clinicians that must be supported with sufficient resources to be successful.

Pharmacology of commonly used analgesics and sedatives in the ICU: benzodiazepines, propofol, and opioids

The ideal sedative or analgesic agent should have a rapid onset of activity, a rapid recovery after drug discontinuation, a predictable dose response, a lack of drug accumulation,and no toxicity. Unfortunately, none of the earlier analgesics, the benzodiazepines,or propofol share all of these characteristics. Patients who are critically ill experience numerous physiologic derangements and commonly require high doses and long durations of analgesic and sedative therapy. There is a paucity of well designed clinical trials evaluating the safety and efficacy of earlier sedative and analgesic agents in the ICU. In addition, the ever-changing dynamics of patients who are critically ill makes the use of sedation a continual challenge during the course of each patient’s admission. To optimize care, clinicians should be familiar with the many pharmacokinetic, pharmacodynamic, and pharmacogenetic variables that can affect the safety and efficacy of sedatives and analgesics.

Effects of a novel benzodiazepine derivative, JM-1232(-), on human gastroepiploic artery in vitro

OBJECTIVE

To investigate the effects of JM-1232(-) on norepinephrine (10(-6) mol/L)- and high K(+) (40 mmol/L)-induced contractions in isolated human gastroepiploic arteries (GEA), and to compare them with the effects of midazolam and propofol. In addition, to investigate whether the benzodiazepine-receptor antagonist, flumazenil, or μ-opioid-receptor antagonist, naloxone, influenced the vascular effects of JM-1232(-).

DESIGN

An in vitro experimental study.

SETTING

University laboratory.

PARTICIPANTS

GEA segments were used from 69 patients undergoing coronary artery bypass graft surgery.

MEASUREMENTS AND MAIN RESULTS

JM-1232(-) produced dose-dependent relaxation effects in the rings. Although these effects of JM-1232(-) were greater than those of midazolam and propofol at high concentrations (10(-5)-10(-4) mol/L), there were no significantly different relaxation effects at the clinical concentrations of 3 × 10(-6) mol/L JM-1232(-), 3 × 10(-6) mol/L midazolam, and 1 × 10(-5) mol/L propofol. In addition, all these effects were independent of the presence of a functional endothelium. Vasorelaxation induced by JM-1232(-) on norepinephrine-preconstricted GEA was inhibited by flumazenil, but not by naloxone.

CONCLUSIONS

These results indicate that JM-1232(-) dose-dependently relaxes smooth muscle in human GEA, this effect being independent of the endothelium. Within the ranges of plasma concentrations achieved in clinical practice, JM-1232(-) had similar vasorelaxation effects to midazolam and propofol. JM-1232(-)-induced vasorelaxation was inhibited by flumazenil, indicating that JM-1232(-)-induced vasorelaxation occurred via peripheral benzodiazepine receptor activation in the GEA.

Sedation, analgesia, and delirium in the critically ill patient

Most critically ill patients receive a myriad of psychoactive medications during their hospital stay. An understanding of the pharmacology of the more commonly used sedative and analgesic therapies enables the clinician to aptly utilize these medications and limit toxicity. A key to the appropriate provision of sedative and analgesic pharmacotherapy is a thorough patient assessment, use of validated monitoring tools, and defined therapeutic goals. Limiting these therapies while optimizing patient comfort has been shown to reduce the duration of mechanical ventilation and reduce intensive care unit (ICU) and hospital length of stay and should be the aim of the multidisciplinary medical team. This review is intended to provide the reader with a fundamental understanding of how to facilitate comfort of the mechanically ventilated critically ill adult patients and how to minimize medication-related toxicities.

Protocolized and target-based sedation and analgesia in the ICU

Administering sedative and analgesic medications is a cornerstone of optimizing patient comfort and minimizing distress, yet may lead to unintended consequences including delayed recovery from critical illness and slower liberation from mechanical ventilation. The use of structured approaches to sedation management, including guidelines, protocols, and algorithms can promote evidence-based care, reduce variation in clinical practice, and systematically reduce the likelihood of excessive and/or prolonged sedation. Patient-focused sedation algorithms are multidisciplinary, including physician, nurse, and pharmacist development and implementation. Key components of sedation algorithms include identification of goals and specific targets, use of valid and reliable tools to assess analgesia, agitation, and sedation, and incorporation of logical medication selection. Sedation protocols generally focus on a) algorithms that incorporate treating sedation and analgesia based upon escalation, de-escalation, or changing medications according to specific targets, or b) daily interruption of sedative and opioid analgesic infusions. Many published sedation protocols have been tested in controlled clinical trials, often demonstrating benefit such as shorter duration of mechanical ventilation, reduced ICU length of stay, and/or superior sedation management compared to usual care. Implementation of sedation algorithms in ICUs is a challenging process for which sufficient resources must be allocated.

Not-so-trivial pursuit: mechanical ventilation risk reduction

As many as half of critically ill patients require mechanical ventilation. In this article, a program of research focused on reduction of risk associated with mechanical ventilation is reviewed. Airway management practices can have profound effects on outcomes in these patients. How patients are suctioned, types of processes used, effects of suctioning in patients with lung injury, and open versus closed suctioning systems all have been examined to determine best practices. Pneumonia is a common complication of mechanical ventilation (ventilator-associated pneumonia), and use of higher backrest elevations reduces risk of pneumonia, although compliance with such recommendations varies. The studies reviewed here describe backrest elevation practices, factors that affect backrest elevation, and the effect of backrest elevation on ventilator-associated pneumonia. Oral care strategies also have been investigated to determine their effect on ventilator-associated pneumonia. Oral care practices are reported to hold a low care priority, vary widely across care providers, and differ in intubated versus nonintubated patients. However, in several studies, oral applications of chlorhexidine have reduced the occurrence of ventilator-associated pneumonia. Although ventilator patients require sedation, sedation is associated with significant risks. The overall goals of sedation are to provide physiological stability, to maintain ventilator synchrony, and to ensure patients' comfort-although methods to evaluate achievement of these goals are limited. Reducing risks associated with mechanical ventilation in critically ill patients is a complex and interdisciplinary process. Our understanding of the risks associated with mechanical ventilation is constantly changing, but care of these patients must be based on the best evidence.

A review of the evidence for music intervention to manage anxiety in critically ill patients receiving mechanical ventilatory support

Critically ill patients receiving mechanical ventilatory support experience profound anxiety with this common treatment modality. Music intervention is one adjunctive therapy that can be implemented to allay anxiety. This article reviews the evidence support music as an adjunctive intervention with mechanically ventilated patients.

Extubation time, hemodynamic stability, and postoperative pain control in patients undergoing coronary artery bypass surgery: an evaluation of fentanyl, remifentanil, and nonsteroidal antiinflammatory drugs with propofol for perioperative and postoperative management

STUDY OBJECTIVE

To compare three anesthetic strategies with respect to the time of extubation after coronary artery bypass graft (CABG) surgery and to assess patient satisfaction with the procedure.

DESIGN

Prospective, randomized, clinical study.

SETTING

Tertiary-care referral center.

PARTICIPANTS

180 cardiac surgical patients undergoing primary CABG from January through June 2004.

INTERVENTIONS

After induction of general anesthesia, patients were allocated to one of three groups. All three groups received a continuous infusion of intravenous (IV) propofol perioperatively and postoperatively. Group 1 (fentanyl infusion group, n = 60) received continuous IV fentanyl infusion perioperatively and postoperatively for analgesia. Group 2 (diclofenac group, n = 60) received fentanyl bolus doses intraoperatively and diclofenac suppository postoperatively. Group 3 (remifentanil group, n = 60) received continuous infusion of IV remifentanil perioperatively and IV fentanyl as an immediate postoperative bolus followed by continuous fentanyl infusion. Duration of postoperative ventilation up to the time of extubation, inotrope requirement, time at which analgesic infusion was discontinued, postextubation arterial blood gas analysis, pain evaluation via visual analog scale, need for rescue analgesia, awareness during surgery, and length of postcardiac surgical unit stay, were evaluated in each patient.

MAIN RESULTS

The diclofenac group exhibited the shortest time to extubation, the least inotrope use, and the fewest rescue doses of analgesic than did patients of the other two groups.

CONCLUSION

Intravenous propofol with bolus doses of IV fentanyl intraoperatively in combination with postoperative nonsteroidal antiinflammatory drugs had the best recovery profile in patients undergoing primary CABG than did the other two regimens studied.

Parameter identification and sedative sensitivity analysis of an agitation-sedation model

Sedation administration and agitation management are fundamental activities in any intensive care unit. A lack of objective measures of agitation and sedation, as well as poor understanding of the underlying dynamics, contribute to inefficient outcomes and expensive healthcare. Recent models of agitation-sedation dynamics have enhanced understanding of the underlying dynamics and enable development of advanced protocols for semi-automated sedation administration. In this research, the agitation-sedation model parameters are identified using an integral-based fitting method developed in this work. Parameter variance is then analysed over 37 intensive care unit patients. The parameter identification method is shown to be effective and computationally inexpensive, making it suited to real-time clinical control applications. Sedative sensitivity, an important model parameter, is found to be both patient-specific and time-varying. However, while the variation between patients is observed to be as large as a factor 10, the observed variation in time is smaller, and varies slowly over a period of days rather than hours. The high fitted model performance across all patients show that the agitation-sedation model presented captures the fundamental dynamics of the agitation-sedation system. Overall, these results provide additional insight into the system and clinical dynamics of sedation management.

Physiological modelling of agitation–sedation dynamics including endogenous agitation reduction

Sedation administration and agitation management are fundamental activities in any intensive care unit. A lack of objective measures of agitation and sedation, as well as poor understanding of the underlying dynamics, contribute to inefficient outcomes and expensive healthcare. Recent models of agitation-sedation pharmacodynamics have enhanced understanding of the underlying dynamics and enable development of advanced protocols for semi-automated sedation administration. However, these initial models do not capture all observed dynamics, particularly periods of low sedative infusion. A physiologically representative model that incorporates endogenous agitation reduction (EAR) dynamics is presented and validated using data from 37 critical care patients. High median relative average normalised density (RAND) values of 0.77 and 0.78 support and minimum RAND values of 0.51 and 0.55 for models without and with EAR dynamics respectively show that both models are valid representations of the fundamental agitation-sedation dynamics present in a broad spectrum of intensive care unit (ICU) patients. While the addition of the EAR dynamic increases the ability of the model to capture the observed dynamics of the agitation-sedation system, the improvement is relatively small and the sensitivity of the model to the EAR dynamic is low. Although this may represent a limitation of the model, the inclusion of EAR is shown to be important for accurately capturing periods of low, or no, sedative infusion, such as during weaning prior to extubation.

Recovery of dynamic balance after additional small divided doses of midazolam given intravenously for sedation

We have previously reported that a dynamic balance test with perturbation stimuli and computerised dynamic posturography sensitively reflected the inhibitory effect on balance of intravenous midazolam sedation given intravenously as a single dose, and recovery time was within 80 min. The purpose of this study was to investigate the recovery of dynamic balance after additional doses of midazolam. Eighteen young adult male volunteers were sedated with midazolam given intravenously. The initial dose was given until the Wilson sedation score reached 3, and an additional dose was given until the same score was obtained 40 min later. They were tested with perturbation stimuli 40, 80, 100, and 120 min after the additional doses had been given. Their recovery time was recorded. The mean (S.D.) initial dose of midazolam was 0.07 (0.005) mg kg(-1), and additional doses were 41 (7)% of the initial dose. The serial changes in bispectral index after initial and additional doses were similar. The recovery time for the dynamic balance test (within 80 min) was the same as that recorded in the previous single-dose study. The recovery time of the psychomotor function test was within 75 min. Additional doses of midazolam aiming for a Wilson sedation score of 3 at a dose about 40% of the initial dose and given 40 min after the initial dose are valid in terms of the maintenance of sedation and recovery of dynamic balance. Complete recovery time, including psychomotor function, was within 80 min of the additional dose of the drug.

Sedation during mechanical ventilation: A trial of benzodiazepine and opiate in combination*

OBJECTIVE

To compare the efficacy of continuous intravenous sedation with midazolam alone vs. midazolam plus fentanyl ("co-sedation") during mechanical ventilation.

DESIGN

A randomized, prospective, controlled trial.

SETTING

A ten-bed medical intensive care unit at a university hospital.

PATIENTS

Thirty patients with respiratory failure who were expected to require >48 hrs of mechanical ventilation and who were receiving a sedative regimen that did not include opiate pain control.

INTERVENTIONS

An intravenous infusion of either midazolam alone or co-sedation was administered by a nurse-implemented protocol to achieve a target Ramsay Sedation Score set by the patient's physician. Study duration was 3 days, with a brief daily "wake-up."

MEASUREMENTS AND MAIN RESULTS

We recorded the number of hours/day that patients were "off-target" with their Ramsay Sedation Scores, the number of dose titrations per day, the incidence of patient-ventilator asynchrony, and the time required to achieve adequate sedation as measures of sedative efficacy. We also recorded sedative cost in U.S. dollars and adverse events including hypotension, hypoventilation, ileus, and coma. Compared with the midazolam-only group, the co-sedation group had fewer hours per day with an "off-target" Ramsay Score (4.2 +/- 2.4 and 9.1 +/- 4.9, respectively, p < .002). Fewer episodes per day of patient-ventilator asynchrony were noted in the co-sedation group compared with midazolam-only (0.4 +/- 0.1 and 1.0 +/- 0.2, respectively, p < .05). Co-sedation also showed nonsignificant trends toward a shorter time to achieve sedation, a need for fewer dose titrations per day, and a lower total sedative drug cost. There was a trend toward more episodes of ileus with co-sedation compared with midazolam-only (2 vs. 0).

CONCLUSIONS

In mechanically ventilated patients, co-sedation with midazolam and fentanyl by constant infusion provides more reliable sedation and is easier to titrate than midazolam alone, without significant difference in the rate of adverse events.

Physiological modelling of agitation–sedation dynamics

Agitation-sedation cycling in critically ill patients, characterized by oscillations between states of agitation and over-sedation, damages patient health and increases length of stay and cost. A model that captures the essential dynamics of the agitation-sedation system and is physiologically representative is developed, and validated using data from 37 critical care patients. It is more physiologically representative than a previously published agitation-sedation model, and captures more realistic and complex dynamics. The median time in the 90% probability band is 90%, and the total drug dose, relative to recorded drug dose data, is a near ideal 101%. These statistical model validation metrics are 5-13% better than a previously validated model. Hence, this research provides a platform to develop and test semi-automated sedation management controllers that offer the significant clinical potential of improved agitation management and reduced length of stay in critical care.

Use of dexmedetomidine in a pediatric heart transplant patient

Dexmedetomidine is a new sedative and analgesic agent that has a unique property of lack of respiratory depression. We describe a pediatric case in which the use of dexmedetomidine enabled us to successfully extubate a 12-year-old heart transplant patient with acute pneumonia after several failed attempts with the use of more conventional sedation.

Excellence in Evidence-Based Practice: Organizational and Unit Exemplars

The University of Iowa Hospitals and Clinics is a recognized leader in evidence-based practice. Creating organizational excellence in evidence-based practice takes leadership and a committed effort at all levels. Building the capacity, culture, and vision at the organizational and unit levels is needed to promote use of evidence in practice. Practical approaches that have been effective in promoting development of an evidence-based practice program and project are outlined. An exemplar describing development and adoption of an evidence-based project to improve sedation management led to improvements in patient care processes and outcomes.

Modeling and control of the agitation-sedation cycle for critical care patients

Agitation-sedation cycling in critically ill patients, characterized by oscillations between states of agitation and over-sedation, is damaging to patient health, and increases length of stay and healthcare costs. The mathematical model presented captures the essential dynamics of the agitation-sedation system for the first time, and is statistically validated using recorded infusion data for 37 patients. Constant patient-specific patient parameters are used, illustrating the commonality of these fundamental dynamics over a broad range of patients. The validated model serves as a basis for comparison of sedation administration methods, devices, therapeutics and protocols. Heavy derivative feedback control is shown to be an effective means of managing agitation, given consistent agitation measurement. The improved agitation management reduces the modeled mean and peak agitation levels 68.4% and 52.9% on average, respectively. Some patients showed over 90% reduction in mean agitation level through increased control gains. This improved agitation management is achieved via heavy derivative feedback control of sedation administration, which provides an essentially bolus-driven management approach, aligned with recent sedation practices.

British Association of Critical Care Nurses position statement on the use of restraint in adult critical care units

Critical care nurses in the United Kingdom have become increasingly concerned about the use, potential abuse and risks associated with physical restraint of patients. Restraint in critical care is not only confined to physical restraint but can also encompass chemical and psychological methods. There are concerns regarding the legal and ethical issues relating to the (ab)use of physical restraint techniques in critical care. The aim of this article was to present the British Association of Critical Care Nurses (BACCN) position statement on the use of restraint in adult critical care units and to provide supporting evidence to assist clinical staff in managing this process.

Pain management in the intensive care unit

Pain management is an essential component of quality care delivery for the critically ill patient. Because outcomes are difficult to predict in the intensive care unit (ICU), high-quality pain management and palliative therapy should be a goal for every patient. For those patients actively dying, palliation may be among the main benefits offered by the health care team. Appropriate palliation of pain begins with the use of effective strategies for recognizing, evaluating,and monitoring pain. Skill in pain management requires knowledge of both pharmacologic and nonpharmacologic therapies. This article focuses on expertise in the use of opiates to facilitate confident and appropriate pain therapy. To optimize palliative therapy, symptoms are best addressed by interdisciplinary care teams guided by models that acknowledge a continuum of curative therapies and palliative care.

Intensive care sedation of mechanically ventilated patients: a national Swedish survey

Sedation in critically ill patients is a complex issue and at the same time an important concept for ensuring patient comfort. The aim of this study was to review the current practice of sedation for patients on mechanical ventilation in Swedish intensive care units (ICUs). Questionnaires were sent by post to head nurses in 89 ICUs with mechanically ventilated patients. By August 2000, 87 (98%) questionnaires had been returned. The results show that mechanically ventilated patients were routinely sedated in 91% of ICUs. Midazolam or propofol in combination with an opioid were the drugs preferred by 76%. Heavy sedation was most usual in 63% of ICUs but, when asked about the sedation level preferred by nurses, 78% chose light sedation (P=0.001). Only 16% used sedation scales. This study indicates that local habits and personal attitudes seem to have a great impact on sedation routines. It therefore appears worthwhile for ICUs to review their practice and, if necessary, to consider implementing sedation scales and sedation guidelines. Research pertaining to potential complications and patient comfort in relation to different sedation levels as well as further validation of the efficacy of sedation scales is needed.